Translating circuit



J. R. CARSON.

TRANSLATING CIRCUITS. APPLICATION-FILED 0m. 10, 1918.

1,418,285. Patented June 6, 1922 Modzlaiiny Source 7 y INVENTQR.

Jolmlfi Carson BY g a M ATTORNEY UNITED STATES PATENT o -"nca JOHN R.CARSON, 015 NEW YORK, N. Y., ASSIGNOR T0 AMERICAN 1 TELEPHONE ANDTELEGRAPH COMPANY, A CORPORATION OF NEW YORK,

Application filed October 10, 1918.

To all whom it may'concern:

Be it known that I, JOHN R. CARSON, residing at New York, in the countyof New York and State of New York, have invented certain Improvements inTranslating Circuits, of which the followingis a specification.

This invention relates to signaling systems, and more'particularly tosystems in which carrier currents are employed for the transmission ofsignals.

The invention has for one of its objects the provision of a translatingarrangement for modulating high frequency oscillations, the. modulatingmeans comprising a two element vacuum tube or other equivalent devicehaving unilateral conductivity. Another object of the invention is toprovide an arrangement of this character capable of use either as amodulator of high frequency oscillations in accordance With signalWaves, or as a modulating'detector for detecting, in

accordance with the homodyne or'heterodyne' system of receiving,modulated high frequency oscillations transmitted from a distantstation. Still another object of the invention has reference to theprovision ofa translating arrangement of the character just described inwhich the 'unmodulated oscillations are ineffective upon the outgoingtransmission circuit when the variable modulating source is inactive, sothat when the arrangement is used as a modulator, the

amplitude of the transmitted oscillations will be directly proportionalto theamplitude of the modulating waves.

"vacuum'tube'1',"having a heated filament 2, and an anodeor plate-3.-Aicircuit-comprising conduc'tors 4".andr5 is associated withthefilamentand' plate ofsaidtube, and at Other and further ob]e cts ofthe invention will be'apparent from the detailed description oftheinvention hereinaftergiven.

The invention may, now. be more fully understood from thefollowilngdescription thereof when read .inyconnection with the accompanyingdrawing, Figures 1, 2 and 3 of which representthree differentdiagrammatic embodiments .ofthe invention; I

Referring to Figure 1,. a translating de-q vice-is shown consisting.- of"atwo element points 6 and 7 said circuit divides, one path ffcontinuingthroughga source of direct cur-I rent 8 and the secondary of atransformer 9, theother path including the second Specification ofLetters Patent. Patented June 6, 1922.

Serial .No. 257,654.

12. A source of modulating waves 15 is associated with said firstmentioned path by means of the transformer 9.

The modulating waves supplied over the circuit 15 may be either lowfrequency signaling waves or high frequency oscillations modulated bymeans of a signal and transmitted from a distant station, depending uponwhether the arrangement is to be used for modulating'high frequencyoscillations in accordance with the signal, or for detecting modulatedhigh frequency oscillations transmitted from a distant station. If thearrangement is to be used for the former purpose, the operation is asfollows:

I Oscillations from. the source 13 and low frequency signaling Wavesfrom the circuit 15 are impressed upon the circuit ofthe tube 1 throughthe transfo-rmerslO and 9v predominant first curvature, the highfrelatedby-means of signal waves at a distant stationare received overthe circuit15, and areimpressed upon 'the tube 1 through the transformer9; .High frequency oscillations from the source 13 are also impressedupon the tube through the transformer 10. If the heterodyne systemofreceiving is employed, the frequency, of the source13 will beslightlydiflerent from'that received over the ,circuit 15, sov thatwaves of beat. frequencywill betransmitted through the transformer 12 tothe outgoing circuit 1Q.

llVherethe homodyne system of receiving is employedpthe, frequencyofthe. source 13 willbe-eq'ual tothatof the high frequency modulatedoscillations; receivedinthe circuit 15, in which case variable lowfrequency waves corresponding to the signal by which the high frequencyoscillations were modulated at the distant station, will be trans- 5mitted through, the transformer 12 to the outgoing'circuit 14.

Where it is desired to prevent the source of unmodulated high frequencyoscillations from affecting the outgoing circuit, except 1 when themodulating source is active, an arrangement such as illustrated inFigure 2 maybe employed. In this arrangement two vacuum tu es 16 and 17are shown, having filaments 18*and 19, and anodes or plates 20 1 and 21respectively. A source of direct current8 has one terminal connected tothe filamnts 18 and 19, andthe *other terminal is connected in parallelto the plates and 21 through the secondary windings of a trans- 20former arrangement 22 through which the circuit 15 is associated withthe tubes 16 and 17. A source of high frequency oscillations 13-isassociated bymeans of a transformer 10 with the common path 23 of twoparallel 25 circuits 24 and 25, said parallel circuits, be-

ing connected to the plates 20 and 21, and including the primarywindings of a transformer arrangement 26, whereby an outgoing circuit 14is associated'with the tubes 16 and 17.

This arrangement is such that when the modulating source associated withcircuit 15 is inactive, oscillations from the source 13 are ineffectiveupon the outgoing circuit 14,

I since the ,source of oscillations is applied to a bridge circuit whichis balanced with re- 'specti to the outgoing circuit.- When how i ever,waves from the circuit-15 are applied. to the tubes 16 and 17, thebalance 1s dis-w 40 turbed, and oscillations will be transmitted throughthe transformer 26 to the circuit 14, having an amplitude proportionalto the degree of the disturbance produced by the .waves from the circuit-15; If, therefore, the

, circuit 15 be associated with a source of low frequency signalingwaves, the high frequency oscillations from the source '13 will bemodulated in accordance with said waves by means of the tubes 16 and17,and modulated high frequency' oscillations will be transmitted throughthe transformer 26 to the circuit 14, the amplitude of said oscillationsbeing directly proportional to the amplitude of the modulating signalingwaves. Where the arrangement is to be usedas a modulating detector,modulated high frequency oscillations will be received from the circuit15, and transmitted through the transformer 22 to the tubes 16 and 17Oscillations from the source 13 will interact with the receivedoscillations in the tubes 16 and'1'7 and low frequencysignals will betransmitted "through the transformer 26 to the circuit 14. These lowfrequency signal waves will be of beat frequency where the the case ofthe circuit arrangement of Figure changed with respectto the tubes 16and 17. A

The outgoing-circuit'14 is associated by means of a transformer 27 withthe common branch 23 of the two parallel circuits 24 and 25, while thesource of oscillations 13 is associated by means of a transformerarrangement 28 with the individual paths of said parallel circuits.

In accordance with thisarrangement, the circuits are normally balancedsothat oscillations from the source 13 are ineffective upon grid circuit23, and consequently do not react upon the outgoing circuit 14. When thebalance is disturbed by waves from the circuit 15, energy is transmittedto the circuit 14 in direct proportion to the amplitude of-,thedisturbing waves. As in 2, the circuit of Figure 3 may be employedeither, for modulating high frequency os cillations from the source 13in accordance with low frequencysignals impressed upon thecircuit 15, orfor the purpose of detecting high frequency modulated oscillationsimpressed upon the circuit 15 in accordance with either the homodyneorheterodyne principle of receiving.

By means of the circuit arrangement above described, a simple and yetefiicient modulating arrangement is provided, which is quite flexible inits operation and is readily adapted to a considerable number of uses.It will also be obvious that the general principles herein disclosed maybe embodied inma'ny other organizations widely different from thoseillustrated Without departin from the spirit of; the invention as definein the following claims:

What is claimed is:

1, In a signaling system, a duplex translating device comprising twoelements hav ing unilateral conductivity, parallel circuits for each ofsaid elements having common 120 branches connected to said elements, asource of vunmodulatedoscillations and an outgoing circuit associatedwith one pair of said parallel circuits, and a source of variableoscillations associated with the other pair 125 of parallel circuits.

2. In a signaling system, a duplex translating device comprisin twoelements havparallel circuits for each of said elements having commonbranches connected to the 'filaments and anodes of said elements, a

oscillations associated withthe other pair of parallel circuits.

3. In a signaling system, a duplex translating device comprising twoelements having unilateral conductivity, parallel circuits for each ofsaid elements having common branches connect'ed'to said elements, asource of unmodulated oscillationsand an outgoing circuit associatedwith one pair of said parallel circuits, and a source of modulatingsignal waves associated with the other pair of parallel circuits.

4. In a signaling system,a duplex translating device comprising twoelements having unilateral conductivity, and each including a heatedfilament and an' anode, parallel circuits for. each of said elementshaving common branches connected to the filaments and anodes of saidelements, a source of unmodulated oscillations and an outgoing circuitassociated with one pair of parallel circuits, and a source ofmodulating signal waves associated with the other pair of parallelcircuits.

5. In a signaling system, a duplex translating device comprising twoelements having unilateral conductivity, parallel circuits for each ofsaid elements having common branches connected to said elements, asource of unmodulated oscillations and an outgoing circuit associatedwith one pair of said parallel'circuits, and a source of variableoscillations associated with the other pair of parallel circuits, andconnections between said sources, said outgoing circuit and said inputand output circuits whereby said first mentioned source produces noeffect upon said outgoing circuit when said second mentioned source isinactive. I

6. In a signaling system, a duplex translating device comprising twoelements having unilateral conductivity, and each including a heatedfilament and an anode. parallel circuits for each of said elementshaving common branches connected to the filaments and anodes of saidelements, a source of unmodulated oscillations and an outgoing circuitassociated with one ,pair of parallel circuits, and a source of variableoscillations associated with the other pair of parallel circuits, andconnections between said sources, said outgoing circuit and said inputand output circuits whereby said first mentioned source produces noeffect upon said outgoing circuit when said second mentioned source isinactive.

7. In a signaling system, a duplex translating device comprising twoelements havingunilateral conductivity, parallel circuits for each ofsaid elements having common) branches connected to said elements, a sour:e of unmodulated oscillations and an outgoing circuit associated withone pair of said parallel circuits, and a source of modulating signalwaves associated with the other pair of parallel circuits, andconnections between said sources, said outgoing circuit and said inputand output circuits whereby said first mentioned source produces .noeffect upon said outgoing circuit when said second mentioned source isinactive.

' 8. In a signaling system, a duplex translating device comprising twoelements having unilateral conductivity, and each includ ing a heatedfilament and an anode, parallel. circuits for each of. said elementshaving common branches connected to the filaments and anodes of saidelements, a source of un modulated oscillations and an outgoing circuitassociated with one pair of parallel circuits and a source of modulatingsignal WH/VBS associated with the other pair of parallel circuits. andconnections between said Sources, said outgoing circuit and said inputand output circuits whereby said first mentioned source produces noefiect upon said outgoing circuit when said second mentioned source isinactive.

9. In a signaling system, a duplex translating device comprising twoelements having unilateral conductivity, circuits for said unilateralelements, individual branches and a common branch, :1 source ofunmodulated oscillations and a source of variable oscillations, one ofsaid sources being associated with the common branch of said circuitsand the other circuit being associated with the individual branchesthereof, and an outgoing circuit associated with said translatingdevice.

10. In a signaling system, a duplex translating device comprising twoelements having unilateral conductivity, each elementineluding a heatedfilament and an anode, circuits for said elements having a common branchand individual branches, the common branch being connected to saidfila-' ments and the individual branches being connected to said anodes,a source of unmodulated oscillations and a source of variableoscillations, one of said. sources being associated with the commonbranch and the other source being associated with said individualbranches, and an outgoing circuit associated with said translatingdevice.

11. In a signaling system, a duplex translating device comprising twoelements having unilateral conductivity, circuits for said elements,said circuits having a common branch and individual branches, at sourceof modulated oscillations and a source of modulating signal waves, oneof said sources being associated with said common branch said circuitsincluding and the other source being associated with said individualbranches, and an outgoing Waves, one of said sources being associatedcircuit associated with said device. a I with said common branch and theother 12. In a signaling system, a duplex trans- 7 source beingassociated with said individual lating device comprising two elementshavbranches, and an outgoing circuit associated 5 ing unilateralconductivity and each includ- With the said device. 15

ing a heated filament and an anode,'circuits In testimony whereof," Ihave signed my for each'of said elements, said circuits havname to thisspecification this 7th day of ing a common branch and individual October1918. branches, a'source of unmodulated oscilla- 10 tions and a sourceof modulating signal .JOHN R. CARSON.

